114 
Loa pap ion is n. sp. 
of exposing the carotid artery, Dr Query mentioned his discovery to the late 
Prof. R. Blanchard, who very kindly suggested my investigating the matter. 
The larval and adult forms of a filaria belonging to the genus Loa were 
identified in a certain proportion of the animals examined, and the problem 
as to their identity or otherwise with the human parasite Loa loa investigated. 
Certain experimental researches were also initiated, but in August 1914, my 
work was interrupted by the war and is therefore incomplete in certain respects; 
I hope, however, to make good these deficiencies later. The investigations 
detailed in this paper were made, partly in the Laboratory of Parasitology, 
partly in Dr Query’s private laboratory, in Paris. 
Acknowledgments. I have to thank Dr L. C. Query and his staff for much 
kind help on all occasions; also Dr M. Langeron, whose suggestions with regard 
to technique were often invaluable. I am indebted besides to Prof. R. T. 
Leiper for several suggestions. Plate IX, fig. 3 is from a water colour by 
Dr E. Miller; the remainder were drawn and coloured bv Madame Blanchard. 
•/ 
I. Description of the adult form of Loa papionis. 
The presence of cuticular bosses in both sexes is the most obvious charac¬ 
teristic of the genus Loa. The single species hitherto recorded is Loa loa 
Guyot 1778 1 . The more important differences between this parasite and the 
one I am about to describe are summarized in Table I. I am inclined to think 
these differences justify the creation of a second species, and have accordingly 
named the worm Ijoa papionis after the baboon in which it was found. 
Technique. The living worms were fixed in 70 per cent, alcohol at 60° C.; 
they were subsequently transferred to cold 70 per cent, alcohol where they 
were left until wanted. Before clearing, they were placed in 0-9 per cent, 
saline for some minutes to enable them to recover from the slight shrinkage 
caused by the alcohol: if this precaution be observed, the measurements made 
before and after fixation are identical. 
The neck or shoulder described or figured by Manson (1912), Penel (1904) 
and Looss (1904) does not exist—at any rate in this species—provided the 
living worm be fixed in hot alcohol. However, this artefact is frequently 
visible after fixation in cold alcohol, and is no doubt produced by the con¬ 
traction of the muscle cells inserted at the level of the base of the cephalic cone. 
In living worms an indentation appears at about this level—first on one side, 
then on the other—during movements of the head; it is never visible during 
rest. 
External measurements. 12 dc? and 12 $$ were taken from the same baboon 
and measured before fixation. The <$<$ measured 27 to 33 mm. in length, 
0-4 to 0-5 mm. in breadth; the $$ measured 63 to 83 mm. in length, 0-55 to 
0-7 mm. in breadth. The maximum diameter is usually reached in both sexes 
1 Skrjabin (1917) describes a parasite to which he gives the name Loa extraocularis. However, 
the cuticular bosses and other characteristic features of the genus are absent from his description, 
which more nearly corresponds to the one usually given for Filaria (?) conjunclivae Addario. 
